Identification by Life Cycle Assessment of the critical stage in the catalytic synthesis of nopol using heterogeneous catalysis

Nopol is a fine chemical obtained from Prins reaction between beta-pinene that is a pine derivative and paraformaldehyde; this alcohol has several applications in the aromas and fragrances industry, agrochemicals, pharmaceuticals and household products. The current knowledge gap with this contribution is evaluate the environmental impacts of nopol synthesis by two alternative processes using the Life Cycle Assessment approach, which was developed according to the methodological structure of ISO standards with a cradle-to-gate scope, analysis that has not been reported so far in the literature. The Life Cycle Inventory was carried out according to primary and secondary data, where Aspen Plus (R) was used. Hierarchist ReCiPe v1.13 (2008) was used as a methodology for the Life Cycle Impact Assessment using the Umberto LCA+ software with the Ecoinvent v3.6 database. The results showed that, in general, raw materials extraction contributes to a much greater extent in the environmental burdens than production process phase. It was found that the hotspot of the process is the solvent; greater environmental benefits were obtained when ethyl acetate was recirculated to the process, despite the additional required unit operations such as distillation tower and heat exchanger. The fossil depletion potential was the impact category with the highest score in points followed by climate change potential and agricultural land occupation potential. The carbon footprint of nopol catalytic synthesis was 13.0 and 37.4 kg CO2-Eq for system with solvent recirculation and without recirculation, respectively, which are less than reported values for a fine chemistry product as an active pharmaceutical ingredient. As options to decrease the environmental burdens of the studied nopol production process, it is proposed to optimize the fossil resources, evaluate the recirculation, replace or decrease solvent amount; also the evaluation of other heterogeneous catalytic systems and appropriate reaction conditions is proposed. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This study evaluates the environmental impacts of nopol synthesis using a Life Cycle Assessment approach, revealing that raw materials extraction contributes more to environmental burdens than the production process phase. Optimization of fossil resources, evaluation of recirculation, replacement or reduction of solvent amount, as well as investigation of other catalytic systems and reaction conditions are suggested as strategies to decrease the environmental burdens of the studied nopol production process.